Can organic amendments replace chemical fertilizers in nickel agromining cropping systems in Albania?

In Albania, ultramafic outcrops cover 11% of the surface and have the potential to support nickel phytomining. In a large-scale in-situ experiment on an ultramafic Vertisols in Pojskë we are studying the influence of agronomical practices on Ni phytoextraction yield of Odontarrhena chalcidica (syn. Alyssum murale). Three cropping systems were compared in three plots in 2016-2017; POJ-1 Plot (0.3 ha) was established with plants that had germinated spontaneously without any treatments; POJ-2 plot (0.3 ha) was covered by plants that had germinated spontaneously and was treated with mineral fertilizer (N50P50K50 kg ha^-1); and POJ-3 Plot (400 m²) was divided in four sub plots, where O. chalcidica was planted at a density of 4 plants m^-2 on which, we neither applied fertilizer, nor NPK fertilizer (N65P65K65), pig (FPM; N260:P105:K260 + 15 kg ha^-1N, P, K) or chicken manure (FCHM; N260:P390:K260 +15 kg ha^-1 N, P, K. Irrigation and mechanical control of weeds was done on POJ-3. After 8 months, shoot Ni concentration, biomass, and Ni yields were higher in O. chalcidica treated with manure and the cost of biomass production was smaller. Nickel yield was more promising (145 kg ha^-1) than in previous field trials. This study highlights that, using manure, the Ni yield increases Ni phytomining net values, thus agromining can become an economically justifiable agricultural cropping system.